Modeling multiple physical flows in two or more interacting physical phases can often become so complex as to require sophisticated computational methods and extensive computer resources. For example, effective modeling of nuclear waste repository systems such as at Yucca Mountain in the state of Nevada to provide time-related heat and moisture flow outcomes for particular storage configurations may require detailed modeling of heat, air and moisture transport processes occurring in a mass of rock of volume of the order of one kilometer cubed and which is invested with shafts, airways, storage bays and corridors and the like. In some cases conventional modeling methods may have difficulty in generating adequately detailed data at a useful pace. Even the best of available computing equipment may lag the calendar. For example, for some problems it appears that a 300-year, three-dimensional, full-mountain hydrothermal and ventilation simulation could take as much as 500 years to run with conventional methods and equipment.
Known solutions of such modeling problems for a given boundary condition often employ a suitable numerical method, referred to as a numerical transport code (hereinafter referenced “NTC”). Numerical transport codes represent a family of engineering software to solve, for example, heat conduction problems in solids using ANSYS; heat and moisture transport problems in porous media using NUFT; or laminar or turbulent flow and transport problems using FLUENT, a computational fluid dynamic (CFD) model.
The component elements of conventional complex simulation models are in some cases quite well developed. A difficulty encountered is that the incorporation of two or more, stand-alone model elements into a coupled simulation may introduce problems including (1) code incompatibilities; (2) source-code-level programming needs; and (3) quality-control problems of large codes developed by multiple groups of independent authors. For example, 3D heat conduction, or nonequilibrium flows of heat, moisture, and a scalar substance transport in saturated/unsaturated medium, can be adequately simulated, with NUFT [4] or TOUGH [21]. Convection, conduction, and radiation in flow channels can be calculated with commercial codes such as ANSYS [22], an engineering simulation package, or FLUENT [23], a CFD software. However, the coupled solution of large, independent codes may require unacceptably long computational time.